How to attach an animation to an empty
You can use an &quot;action&quot; and &quot;action constraint&quot; on the armature to do that.

With the armature selected, go to the dope sheet, select the action editor and use the stash button. That will remove the animation from the armature but keep it in memory for later use.

Now, enter pose mode in the armature, select a bone, go to the constraints part, and add an action:

Parameters for the image above:

The empty as target with channel (X location) and location range
The action to apply with its frame range

Once done for one bone, select them all keeping the bone that has the constraint active, then go to the pose menu, constraints then copy constraints to selected bones.

Back in object mode, you can now select and move the empty to trigger the animation.